Film developing apparatus

ABSTRACT

Automatic film developing apparatus for processing continuous length film, e.g. movie film. Film is pulled in a helical path about a series of upper and lower freely rotatable guide spools mounted on upper and lower shafts. An auxiliary drive roll underlies the peripheries of the spools on the upper shaft, which is resiliently biassed upwardly. When the film tension reaches some preselected value, the upper spools are pulled down into driving engagement with the auxiliary drive rolls, thus reducing the tension. One end of certain upper shafts may be blocked from vertical movement to provide smoother operation under certain conditions.

United States Patent [72] Inventor Edward B. Krause 20 Meadow Wood Road,Trumbull, Conn.

06611 [21] Appl. No. 685,747 [22] Filed Nov. 27,1967 [45] Patented Apr.13, 1971 {54] FILM DEVELOPING APPARATUS 7 Claims, 17 Drawing Figs.

Primary Examiner-Samuel S. Matthews Assistant ExaminerRobert P. GreinerAttorneyMattern, Ware and Davis ABSTRACT: Automatic film developingapparatus for processing continuous length film, e.g. movie film. Filmis pulled in a helical path about a series of upper and lower freelyrotatable guide spools mounted on upper and lower shafts, An auxiliarydrive roll underlies the peripheries of the spools on the upper shaft,which is resiliently biassed upwardly. When the film tension reachessome preselected value, the upper spools are pulled down into drivingengagement with the auxiliary drive rolls, thus reducing the tension.One end of certain upper shafts may be blocked from vertical movement toprovide smoother operation under certain conditions.

Patentd April 13, 1971 6 Sheets-Sheet 1 INVENTOR.

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Edward B. Krause Patented I April 13, 1971 6 Sheets-Sheet 3 INVENTOR.Edward B, K; was? Mailer Warczfl Davis Paten ed "April 13, 1971' 6Sheets-Sheet 5 INVEN Edward B, Kraus'e Patented Agni! 13, 1971 6Sheets-Sheet 6 [dward 1i Kraus'e Alaii'erx Ware8-flawk resiliently urgedaway from auxiliary drive means. Preselected film tension pulls thespools into engagement with the auxiliary drive means, thus reducing thetension on the film.

PRIOR ART AND PROBLEMS Various types of automatic film processingapparatus are well known in the art. Typically, the film is passed inhelical paths around a series of upper and lower guide spools, some ofwhich are driven to advance the film with at least the lower spoolsbeing immersed in the various processing baths. A substantial amount offilm presently being processed does not have sprocket holes along theedges, and is handled by driven friction type spools. Exemplary priorart Pats. are .lurska, US. Pat. No. 3,261,278 and Capstaff US. Pat. No.1,664,735, wherein the guide spools are positively driven at all times.Since a large amount of film will be within the processing apparatus atany given time, control of the film tension is a serious problem. Withprior art apparatus, tension within the film being treated can onoccasion increase due to various causes until the film breaks, orexcessive slackness can develop at some portion of the apparatus. Theseand other difficulties are avoided by the present apparatus.

It has been discovered that the above difficulties may be avoidedaccording to the present invention by normally pulling the film throughthe treating apparatus by a takeup 'roll, with the film being guided onfreely rotatable idler spools,

if means are provided to positively drive certain of the idler spoolsupon occurence of excessive tension.

OBJECTS Accordingly a primary object of the invention is to provide filmdeveloping apparatus which automatically maintains the film tensionwithin prescribed limits. A further object is to provide apparatus ofthe above character wherein a minimum lower tension on the film isassured by normally pulling the film through the apparatus with acapstan pacer roll mechanism.

A further object is to provide apparatus of the above character whereinthe film being processed is guided by a series of normally freelyrotatable spools.

A further object is to provide apparatus of the above character whereinmeans responsive to excessive film tension automatically drives some ofthe normally freely rotatable spools so as to reduce excessive filmtension.

A further object is to provide apparatus of the above THE. DRAWINGS Fora fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings, in which:

FIG. 11 is atop plan view of an exemplary first embodiment invention;

FIG. 2 is a side elevation view of the FIG. I apparatus, partly brokenaway;

FIG. 3 is an enlarged detailed view of the upper left corner of FIG. 2,showing the preferred embodiment of the takeup capstan arrangement;

FIG. 4 is a sectional view taken along line 4-4 in FIG. '3, showing therear of the takeup capstan arrangements;

FIG. 5 is an enlarged detailed view of the upper right corner of FIG. 2,showing the suspension arrangement of a typical upper spool shaft;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5, showing thesuspension of the upper spool shaft and the construction of thepreferred film guide spools, and the relation of the guide spools t0 theauxiliary drive roller;

FIG. 7 is a schematic perspective view of the upper spools and auxiliarydrive assembly, showing a particular arrangement of stops for limitingthe movement of certain spool shafts;

FIG. 8 is a schematic perspective view similar to FIG. 7, showing adifferent arrangement of stops for limiting the movement of certainspool shafts;

FIG. 9 is a sectional view, similar to FIG. 6, showing an alternativeembodiment of stop mechanism;

FIG. I0 is a sectional view taken along line 10-10 in FIG. 9;

FIG. I1 is a perspective view, partly 'broken away, of the stopmechanism shown in FIG. 9;

FIG. 12 is a rear elevation view of an alternative embodiment whereinthe spool shafts are mounted inside the tank for easier adjustment andmaintenance;

FIG. 13 is a perspective view, partly broken away, of the embodimentshown in FIG. 12;

FIG. 14 is a rear elevation view of a further altemative embodiment ofthe inventionwherein the upper spools are immersed in a liquid bath;

FIG. 15 is a sectional view taken along line 15-I5 in FIG. 14;

FIG. I6 is a sectional view taken along line 16-16 in FIG. 14; I

FIG. 17 is a sectional view taken along line 17-17 in FIG.

DETAILED DESCRIPTION Referring particularly to FIGS. 1 and 2, film 20 isfed from a supply reel 22 at the front of the apparatus and is taken upon a takeup reel 24 at the rear of the apparatus. A series of processingtanks 26 between supply reel 22 and takeup reel 24 are filled with thevarious desired fluids for processing film 20. The leftmost tank 26, asviewed in FIGS. 1 and 2, may be the usual drybox, for drying the filmprior to winding on reel 24. A plurality of generally horizontally uppershafts 28 are provided, supporting freely rotatable upper guide spools30. The ends of shafts 28 are supporting in bearing assemblies attachedto the sidewalls of tanks 26, as will be more clearly disclosed below.Underlying each upper shaft 28 is a corresponding lower shaft 32,supporting lower guide spools 34. As is best illustrated in FIG. 14, thecenter of each lower guide spool 34 is preferably aligned with avertical plane halfway between adjacent spools 30. Spools 30 on a givenupper shaft in cooperation with spools 34 on the corresponding lowershaft 32 provides means for guiding film 20 in a helical pathtransversely across the tanks.

As best shown in FIG. II, when film 20 has completed a helical path fromone side of a tank to the opposite side, film 20 passes over the endmostupper spool 30 on a given shaft 28 to the endmost upper spool 30 on theadjacent upper shaft 28, so that the film feeds back and forth laterallyacross the tanks as it proceeds from supply reel 22 to takeup reel 24.

Motor 36 is mounted near takeup reel 24, and drives pacer capstanassembly 38 for forwarding film 20 through the apparatus. In thepreferred embodiment of the invention, each of spools 30 are freelyrotatable on upper shafts 28, and each of spools 34 are freely rotatableon lower shafts 32, so that film 20 is normally pulled through theapparatus by capstan assembly 38. The details of capstan assembly 38 arebest illustrated in FIGS. 3 and 4. As shown in FIG. 3, capstan assembly38 includes driven pacer roll 40 for frictionally forwarding film 20 totakeup reel 24. Roll 40 is driven from motor 36 by belt 42 andtransmission 44. A nip roll 46 squeezes film 20 against the periphery ofdriven roll 40, to increase the traction for forwarding film 20. Idlerwheel 45 is positioned to increase the contact of film 20 on theperiphery of roll 40, further increasing the traction.

In the apparatus as thus far described, tension on the film at variousplaces in the apparatus will tend to increase due to various causes to alevel sufficiently high to injure or break the film occasionally.According to the present invention, auxiliary drive means are providedfor automatically driving the appropriate normally freely rotatablespools 30 so as to maintain the tension within predetermined limits. Afirst embodiment for achieving this result is illustrated in FIGS. 1, 3,5 and 6. As shown in FIG. 6, which affords a rear view of shaft 28, theleft end of shaft 28 extends through vertical slot 48 in sidewall 50 ofits tank 26. The end of shaft 28 is joumaled in bearing housing 52,which is mounted for vertical sliding movement between outwardlyextending tabs 54 on mounting plate 53 attached to wall 50. Bolt 56 isthreaded into bearing housing 52 and secured by locknut 58, and extendsupwardly through an aperture in upper tab 54. Coil spring 60 is mountedbetween upper tab 54 and locknuts 62 on the upper end of bolt 56,whereby bolt 56, bearing housing 52, and shaft 28 are resiliently urgedupwardly. The opposite end of shaft 28 is similarly resiliently mounted.

As best shown in FIGS. 3 and 6, an auxiliary drive shaft 64 underlieseach shaft 28, and has its left end supported in bearing 66 mounted inwall 50. The opposite or right end of shaft 64 extends through theopposite tank wall to right angle drive unit 68 (FIGS. 1 and 3) drivenfrom motor 36. A sleeve 70, which may be of rubber or the like, ismounted on shaft 64 to provide for frictional drive of the flanges ofspools 30, as will be described.

Each upper shaft 28 and the corresponding lower shaft 32, which withtheir spools 3t) and 34 define a helical film guide path, constitutewith the corresponding drive roller 64 positioned between them a filmprocessing station. Any desired number of such stations may be cascaded,with at least the lower shafts 32 and spools 34 of each station beingimmersed in the various film processing fluids.

According to the first major aspect of the invention, when film tensionbecomes sufficiently high at a given station in the apparatus, uppershaft 28 is pulled down against the resistance of springs 60 until theflanges of spools 30 engage sleeve 70. Shaft 64 is driven at a speedsuch that the film on those spools 30 which engage sleeve 70 isforwarded at an overdrive speed somewhat higher than the peripheralvelocity of capstan rolls 40 and 42, thus lowering the tension. Thepercentage overdrive thus given the film may generally be between I and50 percent and more usually between 2 and I percent, with about percentbeing presently preferred. When the percentage overdrive is too high,spools 30 are repeatedly and rapidly pulled down to be driven by sleeve70, resulting in excessive working" of the apparatus and rapid wear ofthe spool flanges. The film tension required to cause engagement betweenspools 3t) and sleeve 70 should be below the desired maximum tension forthe film, and may be adjusted by moving Iocknuts 62.

It has further been discovered that smoother and more reliable operationis obtained if certain selected ends of particular shafts 28 areprevented from moving downwardly. The spools 30 on these selected endsare therefore prevented from being driven by shaft 64. This may beaccomplished, as schematically illustrated in FIGS. 7 and 8, by stopcollars 72 secured (for example by setscrews) to bolts 56 above uppertabs 54. In FIG. 7, collars 72 are employed at the exit ends of thefirst and second shafts 28, i.e., the ends from which the film is fed tothe first spool 30 on the next succeeding shaft 28. Thus, the left endof the first shaft 28 and the right end of the second shaft 28 areprevented from lowering in response to film tension.

In FIG. 8, the exit end of each shaft 28 is prevented from lowering. Theembodiments of FIGS. 7 and 8 are merely illustrative of preferredarrangements which have been found to operate well under particularconditions: selection of other arrangements to suit different processingconditions is well within the scope of one skilled in the art. Springs60 and other details have been omitted in FIGS. 7 and 8 for simplicityof illustration.

FIGS. 9 through 11 illustrate a camming arrangement as an alternative tothe collars 72 with which one or more ends of a selected shaft 28 may beeasily blocked from vertical movement. Referring to FIG. 9, cam shaft 74is mounted through frame member 76 so that its inner or leftmost end asviewed in FIG. 9 is somewhat lower than bearing housing 52. A simple camsurface 78 is mounted on shaft 74 to underlie housing 52. The oppositeend of shaft 74 may be fitted with handle 80 to manually rotate shaft 74to the desired position. In the position illustrated in FIGS. 9 and 1],bearing 52 is permitted to move vertically. If handle 80 and shaft 74were rotated 180, the high portion of end 78 would be positioned beneathbearing 52, thus preventing bearing 52 and the end of shaft 28 fromlowering in response to film tension. FIG. 10

illustrates the similar cam arrangement for the opposite end of shaft28. The illustrated cams permit simple and rapid blocking of selectedends of shafts 28. Other means for accomplishing this function willoccur to one skilled in the art.

FIGS. 12 and I3 illustrate an alternative embodiment of the invention,wherein the mounting assemblies for upper shafts 28 are mounted insidethe tank for easier adjustment and maintenance. As shown therein, plate53 is provided with a mounting bracket 82 which is attached to the innersurface of wall 50 by a pair of screws 84. Preferably, bracket 82 hasslots 86 for receiving screws 84, so that upon loosening screws 84,brackets 82 and the entire shaft assembly 28 including plate 53 andbearings 52 can be lifted from the apparatus.

FIGS. 14 through 17 illustrate a further alternative embodiment of theinvention wherein upper spools 30 are immersed in the liquid bath. Inorder to avoid the necessity to provide liquid seals for shaft 64through wall 50, output drive shaft 88 of right-angle drive 68 extendsthrough wall 50 above the liquid level. Sprocket wheel 90 is mounted onthe end of shaft 88, and by means of chain 92 drives sprocket 94 onshaft 64. Accordingly, drive 68 is positioned above the liquid level,and the problems of providing sealing around shaft 64 are avoided.

The mounting of the right end of shaft 28 is shown in FIGS. I4 and 15.Drive housing 96 is mounted on the inside of wall 50, and enclosessprocket 90 and chain 92. Opposed brackets 98 are attached to the sidesof housing 96 and define therewith opposed vertical slots for slideablyreceiving laterally extending portions 100 on plate 53. The upper endsof brackets 98 are bent horizontally to form supporting fingers I02extending away from housing 96. The upper tab 54 on plate 53 overhangssupporting fingers 102, and has adjusting screws 104 threadedtherethrough to rest on the upper surfaces of fingers I02. Accordingly,the lower limit of movement of plate 53 may be adjusted by means ofscrews 104.

The mounting of the left end of shaft 28 is shown in FIGS. l4, l6 and17. A vertical C-shaped frame member 106 is mounted within the oppositesidewall 50, and includes horizontally extending supporting finger 108.Mounting plate 53 is slideably received within frame member 106, andincludes adjusting screws 110 threaded through a portion 112 of uppertab 54 which overhangs supporting finger I08, so that the lower limit ofmovement of plate 53 and bearing 52 may be controlled by adjustment ofscrew I10. Shaft 28 and plates 53 in the FIGS. 14-I7 embodiment can beremoved from the apparatus merely by lifting.

In the preferred embodiment of the invention, spools 30 and 34 areadapted for handling at least two film widths, while contacting only theedges of the film. This may be achieved by forming the spools withaxially aligned circumferential grooves which are successively narrowerand deeper near the center of the spools, as best shown in FIG. 14. Thegrooves thus define pairs of shoulders such as 114 for supporting a filmof given width, and such as 116, for supporting a film of narrowerwidth.

When the diameter of pacer roll 40 is selected to the optimum value fora given diameter of shoulders 116, as when processing narrow film, achangeover to wider film can be directly achieved by merely splicing thewider film to the end of the narrow film. The wider film will then bethreaded through the apparatus on shoulders 114 without furtherintervention, although the effective overdrivefor the wider film will behigher than would be normally selected, resulting in more than the usualamount of engagement of spools 30 and sleeve 70. When the wider film hasbeen threaded through the entire machine, the small pacer roll 40 may bereplaced with one of larger diameter, resulting in smoother operation ofthe apparatus, at which time the speed of motor 36 may be reduced tomaintain a constant film speed in the apparatus. It should be understoodthat the apparatus may include the customary elevators or film reservesupply units adjacent the supply reel 22 and the takeup reel 24. Sincethese devices are conventional in the art, they have not beenillustrated. Exemplary film reserve supply units are disclosed in US.Pat.

No. 1,664,735,to Capstaff.

As a further important benefit resulting from the invention, theoverdrive provided by shaft 64 and sleeve 70 automatically compensatefor substantial tolerance variations among the diameters of shoulders H4and 116, and among the spool flanges which engage shaft 64 or sleeve 70.Thus, if the designed overdrive is 5 percent, the spool flange diametersmay be as much as nearly 5 percent smaller than the correct value, whilestill providing useful overdrive. This automatically compensates forwear of the apparatus, and permits considerable economies in productionof the original parts.

It may be seen from the above description, together with theaccompanying drawings that the disclosed apparatus automaticallymaintains the film tension within prescribed limits. A minimum amount offilm tension is assured by pulling film through the several stations bymeans of capstan assembly 38. When film tension increases at particularstations to a-point above the desired level, shaft 28 at that stationmoves downwardly under the urging of the increased film tension untilthe peripheries of spools 30 are engaged and driven by sleeve 70 onshaft 64. The amount of film tension necessary to produce engagementbetween spool 30 and sleeve 70 may be adjusted by locknuts 62. The speedof shaft 64 is selected so that film'20 is fonivarded at a speedsomewhat higher than the takeup speed of capstan assembly 38, so thattension is automatically reduced whenever it exceeds the 1 predeterminedlevel. The particular spools illustrated in the drawings permit handlingof more than one film width, with the film being supported only alongthe edges. Smoother and more reliable operation of the disclosedapparatus may be achieved under particular conditions by blockingvertical movement of selected ends of certain shafts 28, as by theexemplary collars 72 (FIGS. 7 and 8), or by the illustrated camsdisclosed in FIGS. 9 through Ill. Various other modifications of theapparatus are disclosed for permitting the ease of maintenance oradjustment, such as the mounting assemblies illustrated in FIGS. 13through 17. The embodiment disclosed in FIGS. 114 through 17 permitsoperation with spools 30 and 34 beneath the liquid level. The disclosedapparatus in its several embodiments is simple and economical inconstruction and is reliable and efiicient in operation.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained and,since certain changes may be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be inte reted as illustrative and not in a lir nitinsense.

It is also 0 be understood that the following c aims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

lclaim:

1. Film processing apparatus, comprising:

A. at least one film processing tank;

B. a first shaft mounted transversely across said tank and supporting aplurality of freely rotatable first film guide spools which aresubstantially restrained from radial motion;

C. a second shaft generally parallel to said first shaft and supportinga plurality of freely rotatable second film guide spools, said first andsecond spools defining a helical path for guiding film to be processed;

D. film supply means for feeding film to said helical path;

E. film drawing means for drawing film from said film supply meansthrough said helical path at a constant rate;

F. an auxiliary driven drive roll mounted parallel to said first shaftand adjacent said first spools, and said drive roll when in contact withsaid first spools adapted to drive film engaged therewith at a greaterrate than film is drawn by said film drawing means; and

G. means independently resiliently mounting each end of said firstshaft, whereby each end thereof is capable of independent movementtowards said drive roll while the other end remains fixed and wherebyupon occurrence of excessive film tension at one of said first spools,it and said first shaft will be pulled toward said drive roll until saidone of said first spools contacts and is driven by said drive roll tothus relieve said excessive film tension condition.

2. Film processing apparatus as defined in claim 1, wherein said firstshaft is mounted for free rotation about the axis of rotation of saidfirst spools.

3. The apparatus defined in claim 1, further characterized by blockingmeans for selectively preventing or permitting downward movement of atleast one end of said upper shaft.

4. The apparatus defined in claim 3, wherein said blocking meansincludes a camming surface selectively positionable beneath at least oneend of said upper shaft.

5. The apparatus defined in claim I, wherein the speed of said driveroll is so selected that film is forwarded at a speed between I and 50percent higher than said constant rate.

6. The apparatus defined in claim 1, wherein the speed of said driveroll is so selected that film is forwarded at a speed between 2 and 10percent higher than said constant rate.

7. The apparatus defined in claim 1, wherein the speed of said driveroll is so selected that film is forwarded at a speed substantially 5percent higher than said constant rate.

1. Film processing apparatus, comprising: A. at least one filmprocessing tank; B. a first shaft mounted transversely across said tankand supporting a plurality of freely rotatable first film guide spoolswhich are substantially restrained from radial motion; C. a second shaftgenerally parallel to said first shaft and supporting a plurality offreely rotatable second film guide spools, said first and second spoolsdefining a helical path for guiding film to be processed; D. film supplymeans for feeding film to said helical path; E. film drawing means fordrawing film from said film supply means through said helical path at aconstant rate; F. an auxiliary driven drive roll mounted parallel tosaid first shaft and adjacent said first spools, and said drive rollwhen in contact with said first spools adapted to drive film engagedtherewith at a greater rate than film is drawn by said film drawingmeans; and G. means independently resiliently mounting each end of saidfirst shaft, whereby each end thereof is capable of independent movementtowards said drive roll while the other end remains fixed and wherebyupon occurrence of excessive film tension at one of said first spools,it and said first shaft will be pulled toward said drive roll until saidone of said first spools contacts and is driven by said drive roll tothus relieve said excessive film tension condition.
 2. Film processingapparatus as defined in claim 1, wherein said first shaft is mounted forfree rotation about the axis of rotation of said first spools.
 3. Theapparatus defined in claim 1, further characterized by blocking meansfor selectively preventing or permitting downward movement of at leastone end of said upper shaft.
 4. The apparatus defined in claim 3,wherein said blocking means includes a camming surface selectivelypositionable beneath at least one end of said upper shaft.
 5. TheapparaTus defined in claim 1, wherein the speed of said drive roll is soselected that film is forwarded at a speed between 1 and 50 percenthigher than said constant rate.
 6. The apparatus defined in claim 1,wherein the speed of said drive roll is so selected that film isforwarded at a speed between 2 and 10 percent higher than said constantrate.
 7. The apparatus defined in claim 1, wherein the speed of saiddrive roll is so selected that film is forwarded at a speedsubstantially 5 percent higher than said constant rate.